Unbeaten American boxer Floyd Mayweather Jr is confident that he can repeat his victory over Argentine brawler Marcos Maidana, whom he tabbed a "dirty fighter" ahead of their September 13 rematch.

Mayweather was pushed to the limit by Maidana when they first fought last May, although the American still won a majority decision to remain undefeated.

"My job is to win," Mayweather said in a press conference Monday in New York, where their five-city press tour opened. "Everyone remembers a winner. That's my legacy."

"I don't need to change my style. The guy who got the loss needs to change his style," he added.

Mayweather said Maidana "gave a tough effort" and "fought his heart out," but also accused the Argentine of not fighting a clean fight.

"It wasn't clean," said Mayweather. "Was I ever hurt? Sure, the shots to the back of the head hurt. Whenever you're in a heated battle, you are going to be sore. It comes with the territory."

"Is Maidana a better fighter than Canelo (Alvarez)? No. (Miguel) Cotto? No. He's just a dirtier fighter. I didn't get a deep gash from a punch. I got it from a head butt," he added.

Maidana was unimpressed with Mayweather's words, saying: "I fight dirty? He's the king of elbows."

The Argentine, who lost his welterweight belt in the first fight, believes he can get the job done this time.

"I keep getting better in each fight, with defense and head movement," he said, as quoted by Boxing Scene. "What (trainer) Robert (Garcia) has done is to fine tune. In the first Mayweather fight, I was a little too anxious, and that's one of the things that Robert helped me fix."

Maidana is also highly motivated to win the rematch as he says the entire country of Argentina will be watching him fight.

"The rematch is a big deal in Argentina," he said. "The entire country watched the first fight, and there's going to be no exceptions in this one. Everybody is going to watch."